Drafting device



(No Model.)

T. F. HORRIGAN.

DRAFTI NG DEVICE 910 655,287. Patented Feb. 25, 1896.

UNITED STATES PATENT OFFICE.

THOMAS F. HORRIGAN, OF BOSTON, MASSACHUSETTS.

DRAFTING DEVICE.

SPECIFICATION forming part of Letters Patent No. 555,287, dated February25, 1896.

Application filed December 18, 1895. Serial No. 572,569. (No model.)

To aZZ whom it may concern:

Be it known that I, THOMAS F. HORRIGAN, of Boston, (Brightom) county ofSuffolk, State of Massachusetts, have invented an Improvement inDrafting Devices, of which the following description, in connection withthe accompanying drawings, is a specification, like letters on thedrawings representing like parts.

My invention relates to drafting appliances for the rapid laying out ofcircles and squares or other figures, as desired.

I have provided a simple and convenient device for quickly laying outcircles, squares, and other figures with accuracy, and my device maytake the place of other well-known drafting-instruments, or it may beused to supplement them,being extremely convenient and capable ofinstant use without special adjustment.

It is frequently the case that for various reasons it is not desirableto use the compasses in drafting various forms of symmetricalfigures-as, for instance, when it is desired to avoid puncturing thepaper or other object by the point of the compass.

In the accompanying drawings, illustrative of my invention, Figure 1 isa top plan view thereof. Fig. 2 is a vertical section on the line .00 a:of Fig. l, and Fig. 3 is a similar section showing the centralpositioning stud or eyelet in enlarged detail.

In the present embodiment of my invention A designates the body portion,which may be of any thin tough substance, preferably transparentcelluloid and also prefer ably circular in form. At its center I providethe positioning-stud (1, (shown in the present instance as an eyelet,)which is loosely mounted on the body portion of the celluloid by meansof the extended flanges a (L The periphery of the disk A is suitablyprotected by a rim a secured thereto. Extending from the center of thedisk I provide a plurality of perforations, preferably arranged insymmetrical order to form the rectangularly-arranged series I) Z) and cThese perforations may be equidistant apart or otherwise arranged, andare adapted to receive a pencilpoint, as illustrated in dot-ted lines atp.

In use the positioning. stud or eyelet is placed over the point which isto be the center of a circle or square and securely held in place by thefinger, as shown in dotted lines at f. The pencil is then placed in theaperture to form the circle desired, if it be a circle, as shown, andthe disk is revolved to produce the desired circle, as shown in dottedlines. If it is a square that it is desired to form, the points aretaken-as, for instance, the points 2 2, &c.and these points are thenjoined by a ruler in the ordinary manner. T 0 make circles or squares ofother sizes the dots 1 3 4:, &c., may be taken, as is clearly apparent.In order to form a triangle, the points, for instance, 2 2 5 may betaken, or any other set, according to the size and kind of triangledesired.

All the perforations may be numbered, and 1 in order to reproduce afigure exactly as the original the device is placed as desired and thepencil is inserted at the same numbers as in the original figure, andthe duplicate is thereby readily formed.

It will be seen that by means of this device figures of varioussymmetrical outlines may be formed with accuracy and dispatch.

I do not desire to limit myself to the form or arrangement herein shown,as various departures therefrom may be made within the scope of myinvention.

\Vhat I claim is 1. A drafting appliance,consisting of a body portionformed of a sheet of thin material, and a positioning-stud looselysupporting, and surrounded by, said body portion, whereby the latter maybe rotated around said stud as a fixed pivot, the said body portionshaving a plurality of perforations at different distances from said studto receive a marking-point, substantially as described.

2. A drafting appliance,consistin g of a body portion centrally mountedon an eyelet, in loose engagement therewith, whereby the same may beproperly positioned and the body portion rotated on said eyelet as apivot, the said body portion having a plurality of perforations toreceive a marking-point at diiierent distances from said eyelet,substantially as described.

A drafting appliance, consisting of a transparent disk, centrallymounted on an eyelet, and having a plurality of perforations,

arranged in series, extending radially from. 10 said eyelet,substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing Witnesses.

THOMAS F. HORRIGAN. lVitnesses:

FREDERICK L. EMERY, LAURA S. MANIX.

